Sifter or chop-grader



3 Sheets Sheet l.

(No Modelj) E. R. DRAVER.

SIFTER 0R @H01D GRADEB..

3 sheets-sheet (No Model.)

EIR. BEAVER, SIETER ORCHOP GRADER.

No, 562,592. Patented June 23, 1896.

vzinw? ZZ'ZQMJSQS. 6. Wm MMM 3 Sheets-Sheet 3. .BBVDRAVBE SIFTER GR GHOP GRADER.

. Patented June 23, 1896.

(No Model.)

AN DREW BGRANAM4 PHDmLrTrfaWASl-IINGTDN. D C.

UNITED STATES PATENT OFFICE.

EMIL R. DRAVER, OF ALLIANCE, NEBRASKA.

slFTER o-R cHoP-GRADER.

SPECIFICATION forming part of Letters Patent No. 562,592, dated June 23, 1896.

Application filed October 7, 1895. Serial No. 564,869. (No model.)

My invention, generally stated, relates to sifters or separators for effecting the various separations required in the manipulation of mill-stock; but, more specifically stated, relates especially to that class of sifters or chopgraders wherein the stock is made to travel, in various desired directions, over a substantially plane surface, by a proper arrangement of partitions or channel-walls and propellingsurfaces, under a gyrating or other proper i motion on the machine.

A type of the said class of machines is shown in my prior United States patent, No. 536,781, issued to me of date April 2, 1895.

The machine herein shown and described discloses some of the features of construction set forth and claimed in my said prior patent.

My present invention is directed to two features of improvement.

One feature is directed to an improvement in the propelling-surfaces, with a view of' more quickly relieving the bolting-cl'oth, orsiftingsurface, from the impure stock or tailings, so as to render a larger area of the boltingcloth more quickly effective on the pure stock, and thereby greatly increase the capacity of the sieve.

The other feature of myv invention is directed to an improvement in the general construction of the machine, whereby the collecting-channel for the flour and the collecting-channel for the cuts maybe increased or decreased, relative to each other, at will, for varying, at Will, the point of cut-off on the cloth which marks the separation of the sifted material into the said` two classes of iiour and Mcuts, respectively, according to the character and condition of the stock.

To the ends above stated, my invention consist-s of the novel devices and combinations of devices hereinafter described, and defined in the claims. The said invention is illustrated in the accompanying drawings, wherein, like letters referring to likeparts throughout the several views- Y Figure l is a perspective view showing` a working machine in operative positionwith some parts broken away. Fig. 2 is .a plan view of the sieve-box with some parts broken away. Fig. 3 is a view of a pair of sieves detached from the sieve-box, one of the said sieves being shown in plan and the other in horizontal section on the line of Fig. 4. Fig. -l is a vertical longitudinal section on the line 002 .r2 of Figs. 3 and 5, looking from y the left toward the right withrespect to Fig. i 5. Fig. 5 is avertical cross-section on the line 003 of Figs. 3 and 4, looking from the right toward the left with respect to said views or toward the front of the machine.

i Fig. 6 is a detail in perspective, showing the device for 1 operating the variable cut-off. Fig. 7 is a detail in perspective, showing the crank-handle for operating the star-wheel shaft shown in Fig. 6. Figs. 8 to l2 illustrate a modification in the construction of the variable cut-off devices. Said Fig. 8 is a view showing a pair of detachedsieves in horizontal section on the line m4 c4 of Fig. 9. Fig. 9 is a longitudinal section on the line x5 of Fig. 8, looking from the 4front toward the rear. Fig. l0 is a vertical cross-section on the irregular line no m6 of Fig. 8, looking from the right toward the. left. Fig. ll is a detail in perspective for showing the action and the controlling devices for the cut-off gates. Fig. l2 is a detail in section, showing a part of one of said controlling devices.

Having regard, first, to Fig. l, the numeral l represents` the door, and 2 represents the ceiling or overhead structure of a room in a mill or other building. i

The numeral 3 represents the sieve-box, shown as of the form generally used in the class of sitters and chop-graders which are subjected to a gyrating motion. In practice said sieve-boxes are usually equipped with a series of sieves and imperforate collectingsurfaces, one above the other, at different levels. The said box 3 is suspended by hang` IOO ers 4 from overhead timbers 5, secured to the ceiling 2 or other support. The said hangers 4 connect to the timbers 5 and to the box 3 by ball-and-socket or ot-her universal joints G, so as to permit the gyratin g motion. A crank* pin 7 on the crank-disk 8 connects with the box in any suitable way. The crank-disk S is iixed to the top of the vertical shaft or spindle 9, which is seated in the bearing-pedestal 10, iixed to the floor 1. The shaft 9 is provided with pulley 11, which is connected, as shown, by cross-belt 12 with a pulley 13 on the lineshaft 14, one bearing for which is shown at 15.

Vith the mountings and driving connections above described it is obvious that the sieve-box 3 will receive a gyrating motion substantially in the horizontal plane. Rods 16, depending from the overhead structure, support the main feedspout 17 with branches 17, which connect with the sieve-box 3, by flexible feed-bags 18, at the proper points for the supply of the chop or untreated stock to the sieves 19.

The numeral 2O represents the flour-deliverybags. 21 represents the cuts-delivery bags, and 22 represents the tailings-delivery bags. The inlets or months of the said delivery-bags, wherever shown in the other views,r are marked with the same numbers as the bags themselves. The said several deliverybags 20, 21, and 22 connect with suitable chutes for directing the material wherever desired. The said chutes are not shown, but the upper ends of the same are assumed to be i1)1elosed by the casing 23. (Shown in Fig. 1.

Directing attention now to the construction of the sieves 19, the same will be best under.- stood from an inspection of Figs. 2 to 7, inclusive. A pair of companion sieves 19 stand abreast or in a common plane within the sievebox 3, and are supported thereon in any suitableway. The bolting-cloth or sifting-surface c is supported in the skeleton frame 19 at the properlevelinthecustomaryway. Supported by the sieve-frame 19, below the bolting-.cloth c, is an imperforate collecting-surface c', of canvas or other suitable material. In the form shown in the main views the collecting-surface c is set on an incline sidewise, as best shown in Fig. 5. The walls of the sieveeframe 19 are .of the proper construction to so support said collecting-surface c.

A longitudinal vertical partition c2, supported from the end walls of the sieve-frame, divides the sieve-frame 19, both above and below the bolting-cloth c, into longitudinal compartments or channels. The two upper channels, above the bolting-cloth c, communicate, at their opposite ends, through passages in the partition c2, as shown at c3 and c4, respectively, for purposes which will presently appear. The said partitions c2, below the bolting-cloth c, are cutaway, as shown at c5 and c6, respectively, in Fig. 4. A sliding partition-section c7 as is applied to the fixed part of the partition c2 below the cloth c, as

The longitudinal section c7 of the cut-offl c7 c8 is provided with pins o9, adapted to be engaged by the teeth of a star-wheel cw, on the inner end of a hand-shaft c, journaled in the sieve-frame 19 and the partition c2 below the bolting-cloth. The hand-shaft c extends to the exterior surface of the outside wall of sieve, and is of angular form in crosssection, for the application of the crank-handle wrench C12 thereto, through holes cl3, provided for that purpose in the sieve-box 3. Angle-iron keepers 014 prevent the lateral displacement of the cut-off c7 o8. By the said parts o9 to cl2, inclusive, it is obvious that the cutoff device c7 a8 may be moved in either direction, lengthwise of the collecting-surface c', and be thereby made either to extend or to close the passage c6 in the partition c2 below the cloth c. By noting the location of supply or feed inlets 18 to the channels above the cloth c, and the location of the respective outlets 20, 21, and 22 for the flour, the cuts., and the tailings, respectively, as best shown in Figs. 1 and 3, it will be obvious that the cutotf c7 c8 will operate to increase or decrease the flour-channel part or the cuts-.channel part of the collecting-surface c below the bolting-cloth c. Hence, by moving the said cut-off one way or the other, the point of cutoft on the bolting-cloth inay be varied at will, s o as to throw more or less of the stock, sifted through the cloth c, into the flour-channel, or into the cuts-channel, at will. This is a great convenience, because the amount of sifted stock suitable for lour will vary, according to the character and the condition of the chop, the motion or condition of the sieve, dac. Hence, for the greatest efficiency of the sieve, some kind of variable cut-off must be provided for throwing more or less of the pure sifted stock into flour or into cuts, as may be desired.

A modified form of cuteoft device is shown in Figs. 8 to 12, which will be described later on.

Directing attention now to the devices for propelling the stock over the cloth or siftingsurface c, it has already been noted that by the partition c2 the sifting-surface is divided into two channels, which communicate, at their opposite ends, through the passages c3 c4. To the said partitions c2 are iixed shelves d, above the level of the bolting-cloth c, but below theloading-level of the sieve. The said shelves d project Outward toward the centers of the channels, and are wedge-shaped in cross-section, as shown best in Fig. 5. The

partition.

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provided with transverse corrugations or raised propelling-surfaces d' on their upper surfaces, which are shown of angular form of unequal slope, With their steepest surface facing in the direction of the stocks travel. l/Vith the said shelves d applied to the said partition o2, as shown, and with the crankdisk 8, turning in the direction shown by the arrow thereon in Fig. 1, the stock will travel in the direction shown by the arrows in Fig. 3, under the gyrating motion on the sieve.

The position ofthe feed-bag or inlet 1S marks the head, and the position of the tailings bag or outlet 22 marks the foot of the channel on the sifting-surface c, through which channel the stock, or more or less of the same, travels under the gyrating motion on the sieve. The cloth or sifting-surface c is, of course, made of coarser mesh toward `thetailings-delivery end of the same, or

throughout that portion of the channel on the cloth c which overlies that part of the collect-ing-surface c leading to the cuts-outlet 2l.` Thetailings-outlet 22 is separated from the flour-channel bythe partition c2 and from the end of the cuts-channel by a vertical crosspartition C15. At a point directly over the tailingsoutlet 22 the sifting-surface c is composed of a screen-section o16, of sufliciently coarse mesh to pass all of the tailings, but to hold the locust-seeds, peas, beans, grain, or other material which is used for keeping clean the bolting-cloth c.

Operation: Having regard now to the operation, let it be assumed that the sieve is in stock. Then, under the gyrating motion on the sieve, with the crank turning in the direction shown by the arrow in Fig. l, and the Vsaid shelves d located on the particular channel-Wall formed by the partition c2, as shown in Figs. 2 to 5, the stock will travel in the direction shown by the arrows in Fig. 3, and, throughout its travel, will be subjected tothe sifting action of the bolting-cloth or surface c. The pure stock of proper iineness, such as the flour and the cuts, will thereby be successively sifted through thebolting-cloth and be collected by the proper portions of the underlying imperforate surface c and directed to the proper outlets 20 and 2l, provided for for the flour and cuts, respectively, while the bran, coarse stock, the., will be `carried forward to the coarse screen-section c16 and be delivered therethrough into the tailingsoutlet 22. The locust-seeds, grain, or other cleaning materials will pass onward, over the screen-section o16 and through the passage c4, into the receiving end of the channel and continue to travel7 in an endless circuit, over the sifting-cloth or surface c.

In the above-noted action of the collectingsurface c the sifted stock received thereonis propelled lengthwise thereof, through the proper channels, for the flour andthe cuts, respectively, in virtue of being s et on airin-` incline, so as to make the imperforate surface itself act to propel the material, as fully l to load the same to a point above the level of l the shelves d. Let it also be assumed that the stock has been subject to the motion of the sieve for sufficient time to permit the finer and heavier particles or purer stock to have collected, by4 gravity, into a lower strata on the face of the bolting-cloth, and the lighter, coarser, and less pure stock to have collected into an upper strata at and nearthe top of the whole body of stock. The said lower strata may, for further distinction, be

assumed to be sufficiently fineto be siftable through the given bolting-cloth, if given a chance, and the said upper strata may be assumed to be so coarse or light, or both, as to be non-siftable or tailings stock for the given cloth. Hence, the quicker the tailings or non-siftable stock is disposed of the quicker the pure or siftable stock can be brought into contact with the cloth and be sifted.

`This is just exactly the result obtained by my shelf d, in cooperation with the channelwalls of the sieve.

motion and supplied with chop or untreated j As near as I can make out the action is as follows: Under the gyrating motion on the` 2 sieve-box the said shelf d will tendto horizontally splitapart the upper and the lower lstratas of the stock, and will, I know, as a matter of fact, propel theupper strata at a lmuch more rapid rate than the lower strata. As the shelf swings outward into the body of the stock in the channels b the upper strata will tend to pile up or get on `top of the shelf d, on account of inertia, while the under strata will tend to crowd or Wedge into the space between the shelf and the top of the cloth. At the limit of the outward throw of the shelf d it will tend to throw the stock above the same upward and forward inthe 4line of travel, while theunder surface of the shelf will tend to throw the stock below the same downward and forward against the face of the cloth. j This retards the lower strata and accelerates the upper strata. The wedge shape of the shelf heightens the action, inasmuch as it affords a more ready clearance .from the stock both above and below the shelf at the backward or releasing throw of the shelf, but produces a greater wedging action from the under surface of the shelf on the stock between the shelf and the cloth at the outward throw.

Otherwise stated, the wedge shape enables `the shelf cl to increase the resistance on the `lower strata' and increase the acceleration on the upper strata, while at the same time af- IOO Ilo

fording sufficient increased clearance or ease of release of the stock between the shelf and the cloth to avoid clogging. Hence, under this peculiar action, both stratas may, possibly and probably, move faster than they otherWise would; but the upper strata moves much more rapidly than the lower. Theunder strata is made to hug the cloth, and the upper strata is given the utmost freedom to advance under the propelling action of the shelf. The shelf not only thus tends to propel the upper strata more rapidly than the lower, but also tends to prevent the upper strata from becoming remixedwith the lower strata of the stock. Hence, the general effect is to Separate the impure from the pure stock and advance or propel the upper strata or impure stock much more rapidly than the lower strata or pure stock. The impure stock is therefore more rapidly eliminated and carried off as tailings, while the pure stock, being thus unimpeded and comparatively uninterfered with by the impure stock, more rapidly collects onto the cloth or sifting-surface and becomes more rapidly and thoroughly subjected to the sifting action. Hence, the efficiency of the bolting-cloth or other sifting-surface is greatly increased; or, in other words, any given area or amount of sifting-surface will do much more work in any given time. The above statement as to the action will apply whether or not the shelf is provided with the corrugations Vor ribs d on its face; but the addition of the said corrugations or ribs d heightens or increases the propelling action, especially on the upper strata or impure stock.

By actual usage I have demonstrated the efficiency of the improvement in propellingsurfaces above described, and I know that the general effect is to propel the top strata or impure stock much more rapidly than the lower strata or so-called pure stock, and that the capacity of the sieve is greatly increased. I do not, however, undertake positively to say that the exact philosophy of the peculiar action has been stated with absolute precision or correctness. When in motion, the general effect can be readily seen; but the exact action of the shelf on the particles of the stock within the channels, whereby that effect is reached, cannot well be seen by the eye. I believe, however, that the explanation herein given is substantially correct.

The proper heightof the shelf d, above the cloth at, for any gi ven desired load, or depthv of stock, on the sieve, and the proper lateral extension of the said shelf, toward the center of the channel, must all be determined by eX- periment, with respect to any given channel. I have found, however, that good results can be secured with a shelf of from one and threequarters to two inches in lateral extent, and height of from one-half to three-quarters of an inch above the level of the cloth.

The shelf has been shown as cooperating with a horizontal cloth or sifting-surface, and as occupying a horizontal position; but its angle to the cloth may probably be varied to a considerable extent. Such a shelf can also be made to cooperate with a cloth or siftingsurface, which is set on an incline, as shown in my prior patent, No. 536,781, hereinbefore noted, provided it be set to project from the proper wall of the channel or sieve. The said shelves d may be disposed in a great many different ways, relative to the channel-walls, for the proper cooperation with said walls, under the gyrating or other proper motion on the sieve, to propel the stock in any desired direction. The shelf may itself vary in construction.

llfodt'jicaton n out-adwces. In the modification shown in Figs. 8 to 12, inclusive, the central partitions f of the sieve-frames are provided, below the bolting-cloth, with a scries of pivoted doors f', opening from the cutschannel into the flour-channel of the imperforate collecting-surface g, and a correspon ding series of cooperating transverse pivoted partitions or dampers f2, with crank-armsfs, which arms operate, when the damper is up, to lock the cooperating doors f in their closed position, as best shown in Figs. IO and 1]. Vhen the damper f2 is down, so as to operate as a transverse partition in the cuts-channel, the crank-arm f3 will be up, away from the cooperating door f', and the door f will then be free to open, under the motion on the sieve, as shown in Fig. Il, thereby affording a passage from the cuts-channel into the iiourchannel. The damper-shafts extend through the outside wall of the sieve-frame, as shown in Figs. 8, IO, and I2, and are of angular form in cross-section at their outer ends. A corresponding series of wrench-action cranks f4 work through holes f5 in the sieve-box 3, and are held in engagement with the dampershafts by means of keeper plates f6 and springs j' 7, applied to the sieve-box 3, as shown best in Fig. 12. The lever-arm of the crankwrench f4 is in the form of a spring-latch f8, which may be made to engage with either of a pair of notches fg, on opposite sides of the damper-shaft axis, to hold the .damper either in its closed or open position.

With the construction above described it is obvious that more or less of the dampers f2 may be closed or opened from the head toward the delivery end of the cuts-channel, and that thereby the cooperating doors f in the partition or channel wall f will either be left free to open, or be locked shut. Hence, more or less of the collecting-surface gand of the bolting-cloth or sifting-surface c may be appropriated to our or to cuts, as may be needed, to best meet the condition of the stock, motion on the sieve, &c. The general effect is therefore the same as with the form of construction shown in the principal views. This variable cut-off, operative at will, to

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vary the appropriation of the collecting-suri face for making the cut-offs or separations come earlier or later in the travel of the stock, is a new departure in this class of machines.

The sieves, as shown in Figs. 8 to 12, have walls of equal depth; or, otherwise stated, the collecting-surface g is horizontal. The stock is made to travel in the proper direction, through the said collecting-channel, by means of propelling-surfaces 71 in any suitable form applied to the proper channel-walls, in any proper way, with due regard tothe motion on the sieve.

In respect to both features of the invention herein disclosed, it will be understood, of course, that many changes or modifications in the details of the construction might be made without departing from the spirit of my invention.

It must also be understood that a gyrating motion on the sieve 'is not absolutely essential. An oblique or shaking motion, at an angle to the line-guides, will answer the purpose. The gyrating motion, however7 is the one generally used.

Vhat I claim, and desire to secure by Letters Patent of the United States, is as follows:

1. In a sieve mounted to swing in substantially a horizontal plane, the combination with channel-walls extending transverselyuof the sieves movement, lof a shelf which is wedge-shaped in cross-section and projects laterally inward from one of said walls, above the sifting-surface, with its main dimension also extending transversely of the sieves movement, whereby, under the motion of said sieve, said shelf will be moved laterally against the stock to split and to propel the strata of the same at different rates of speed, substantially as described.

2. ln a sieve, mounted to swing s ubstantially in a horizontal plane, the combination with the sieve-walls,bolting-cloth and collecting-surface, of an upper partition dividing the cloth into parallel communicating channels, through which the stock travels over the surface of the cloth, an under partition dividing the collecting-surface into parallel collecting-channels, for different separations, as one for flour and the other for cuts, and a cut-off device operative on said under partition, to

vary the division or relative appropriation made thereby, of said collecting-surface, for appropriatin g more thereof to any given separation, as moreA to iiour and less to cuts, or vice versa, substantially as described.

3. In a sieve, mounted to swing substantially in a horizontal plane, the combination with the sieve-wall, bolting-eloth and collecting-surface, of the upper partition dividing the cloth into two parallel communicating channels, the under partition dividing the collecting-surface into two parallel collectingchannels, one for our and the other for cuts, one or more passages in said under partition, and one or more cut-off devices, arranged to open or close more or less of said passage or passages in said partition and stop the entrance, to the cuts-channel, from the collecting-surface, substantially as and for the purpose set forth.

4. The combination with the sieve 19, having the central partition c2 extending above and below the cloth, as described, and provided with the passage c2 through its under portion, the supply-inlet 18 and the delivery-outlets 20, 21 and 22, arranged relative to each other and the said partitions, as described, the cut-off device c7 es, movable lengthwise of the collecting-surface, and means for controlling or operating said cut-0E device from the lexterior of the sieve and the sievebox, substantially as and for the purpose set forth.

5. The combination with the sieve 19, having the partition c2 extending above and below, the bolting-cloth and provided, in its underneath portion, with the passage c6, of the feed-inlet 18 and the outlets 20, 21 and 22, arranged relative to each other and said partition, as described, the cut-off device c7 08, applied, as described, the pins e9 on the cut-off section c7, the star-wheel and shaft, and the crank-handle wrench, all arranged and operating substantially as described.

In testimony whereof VI aflix my signature in presence of two witnesses.

EMIL R. DRAVER. Witnesses:

Jas.' F. WiLLrAMsoN, E F. ELMORE. 

